Supremes to EPA: drive down those CO2 emissions

In a 5-4 decision the Supreme Court today ruled that the EPA is indeed on the hook for regulating carbon dioxide emissions from vehicles. The case was brought by the state of Massachusetts which alleged that the CO2 emissions from vehicles, which worsen global warming, were harming the state in part by raising sea level and swamping shoreline dwellers. (See the AP story here.)

The justices’ decision is pretty interesting to take a look at — they get a little snippy with each other. (Read both sides of the Supreme Court decision here.)

The majority opinion, written by Justice John Stevens, and signed by justices Anthony Kennedy, David Souter, Ruth Bader Ginsburg and Stephen Breyer, states:

Under the (Clean Air) Act’s clear terms, EPA can avoid promulgating regulations only if it determines that greenhouse gases do not contribute to climate change or if it provides some reasonable explanation as to why it cannot or will not exercise its discretion to determine whether they do. It has refused to do so, offering instead a laundry list of reasons not to regulate, including the existence of voluntary Executive Branch programs providing a response to global warming and impairment of the President’s ability to negotiate with developing nations to reduce emissions…

…Because greenhouse gases fit well within the Act’s capacious definition of “air pollutant,” EPA has statutory authority to regulate emission of such gases from new motor vehicles…

…A reduction in domestic emissions would slow the pace of global emissions increases, no matter what happens elsewhere. The Court attaches considerable significance to EPAs espoused belief that global climate change must be addressed…

…The fact that (Department of Transportation’s) mandate to promote energy efficiency by setting mileage standards may overlap with EPA’s environmental responsibilities in no way licenses EPA to shirk its duty to protect the public “health” and “welfare.”

Chief Justice John Roberts filed a dissenting opinion joined by justices Antonin Scalia, Clarence Thomas and Samuel Anthony Alito that told the majority they were being duped. Scalia also filed his own dissenting opinion, that the same crew all signed on for. From Roberts:

Petitioners’ difficulty in demonstrating causation and redressability is not surprising given the evident mismatch between the source of their alleged injury — catastrophic global warming — and the narrow subject matter of the Clean Air Act provision at issue in this suit. The mismatch suggests that petitioners’ true goal for this litigation may be more symbolic than anything else. The constitutional role of the courts, however, is to decide concrete cases — not to serve as a convenient forum for policy debates.